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Alkylated benzothienobenzothiophenes are an important class of organic semiconductors that exhibit high performance in solution-processed organic field-effect transistors. In this work, we study the near-edge x-ray absorption fine-structure (NEXAFS) spectra of 2,7-didecyl[1]benzothieno[3,2-b][1]benzothiophene (C10-BTBT) at both the carbon and sulfur K-edges. Angle-resolved experiments of thin films are performed to characterize the dichroism associated with molecular orientation. First-principles calculations using the density functional theory-based many-body x-ray absorption spectroscopy (MBXAS) method are also performed to correlate the peaks observed and their dichroism with transitions to specific antibonding molecular orbitals. Interestingly, the dichroism of the dominant, lowest energy peak is opposite at the carbon and sulfur K-edges. While the low-energy peak at the carbon K-edge is assigned to carbon 1s → π* transitions with transition dipole moment (TDM) perpendicular to the planar BTBT core, the dominant low energy peak at the sulfur K-edge is assigned to sulfur 1s → σ* transitions with TDM oriented along the long axis of the BTBT core. These differences at the sulfur and carbon K-edges are understood through the MBAXS simulations that find a reordering of the energy of the lowest energy π* and σ* transitions at the sulfur K-edge due to the strong localization of the σ* orbital over the sulfur atom. This work highlights differences in the NEXAFS spectra of organic semiconductors at carbon and sulfur K-edges and provides new insights into peak assignment and x-ray dichroism relevant for studying the molecular orientation of organic semiconductor films. [ABSTRACT FROM AUTHOR]

Action spectroscopies use a readout created by the action of light on the molecules or material rather than optical absorption. Ultrafast 2D photocurrent and 2D fluorescence spectroscopies are two such action spectroscopies. Despite their utility, multidimensional action spectroscopies suffer from a background created by incoherent population mixing. These backgrounds appear when the action of one molecule impacts that of another, creating a signal that mimics a fourth-order population response but is really just the convolution of two linear responses. The background created by incoherent mixing is often much larger than the desired foreground signals. In this paper, we describe the physical mechanisms that give rise to the incoherent signals, drawing Feynman paths for each. There are three variations of incoherent signals, differing by their pulse ordering. They all have the same phase dependence as the desired fourth-order population signals and so cannot be removed by standard phase cycling, but they do differ in their polarization responses and dephasing times. We propose, and implement, a spectrometer design that eliminates the background signals for isotropically oriented samples, leaving only the desired fourth-order 2D action spectra. Our spectrometer utilizes a TWINS interferometer and a pulse shaper interferometer, each driven with a different white-light source so that the pulse pairs within each interferometer are phase stable, but not between the two. The lack of phase stability between the two interferometers eliminates two of the three incoherent responses. The third incoherent response is eliminated with the polarization scheme ⟨0, π/2, π/4, π/4⟩. Our spectrometer also enables both 2D photocurrent and 2D white-light spectra to be collected simultaneously, thereby enabling a direct comparison between action and optical detection under identical conditions and at the exact same position on the sample. Using this spectrometer and photovoltaic devices made from thin films of semiconducting carbon nanotubes, we demonstrate 2D photocurrent spectra free of incoherent background. [ABSTRACT FROM AUTHOR]

Deposition of epitaxial oxide semiconductor films using physical vapor deposition methods requires a detailed understanding of the role of energetic particles to control and optimize the film properties. In the present study, Ga 2 O 3 thin films are heteroepitaxially grown on Al 2 O 3 (0001) substrates using oxygen ion beam sputter deposition. The influence of the following relevant process parameters on the properties of the thin films is investigated: substrate temperature, oxygen background pressure, energy of primary ions, ion beam current, and sputtering geometry. The kinetic energy distributions of ions in the film-forming flux are measured using an energy-selective mass spectrometer, and the resulting films are characterized regarding crystalline structure, microstructure, surface roughness, mass density, and growth rate. The energetic impact of film-forming particles on the thin film structure is analyzed, and a noticeable decrease in crystalline quality is observed above the average energy of film-forming Ga + ions around 40 eV for the films grown at a substrate temperature of 725 ° C. [ABSTRACT FROM AUTHOR]

The on-demand assembly of 2D heterostructures has brought about both novel interfacial physical chemistry and optoelectronic applications; however, existing studies rarely focus on the complementary part—the 2D cavity, which is a new-born area with unprecedented opportunities. In this study, we have investigated the electric field inside a spacer-free 2D cavity consisting of a monolayer semiconductor and a gold film substrate. We have directly captured the built-in electric field crossing a blinking 2D cavity using a Kelvin probe force microscopy–Raman system. The simultaneously recorded morphology (M), electric field (E), and optical spectroscopy (O) mapping profile unambiguously reveals dynamical fluctuations of the interfacial electric field under a constant cavity height. Moreover, we have also prepared non-blinking 2D cavities and analyzed the gap-dependent electric field evolution with a gradual heating procedure, which further enhances the maximum electric field exceeding 109 V/m. Our work has revealed substantial insights into the built-in electric field within a 2D cavity, which will benefit adventures in electric-field-dependent interfacial sciences and future applications of 2D chemical nanoreactors. [ABSTRACT FROM AUTHOR]

Polyamide nylon 6 (PA6) films were fabricated using a solution casting method and the films were doped with SbCl5. The electrical conductivity increased with the dopant concentration due to the increase in formation of radical cations through the charge transfer from the isolated double bonds (–C=O–) in the polymer chains. The DC electrical conductivity reached a maximum of 0.01 S/cm for 0.5 ml SbCl5 doped films. Structural and optical characteristics of the pure and doped films were examined using Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), X-Ray Diffraction (XRD), and Ultraviolet-Visible (UV-Vis) absorption spectra. The doped films exhibited discernible shifts in the optical band gap energy. The direct band gap values of PA6 films were reduced from 4.5 eV to 1.7 eV when doped with 0.5 ml SbCl5. ATR-FTIR spectral studies, and optical studies indicated the formation of charge transfer complexes with the amide group of nylon 6, resulting in the electrical conduction. The XRD studies disclosed the reduction in the crystallinity of the doped films. The thermal stability was studied using differential scanning calorimetry (DSC) and thermogravimetric analysis-derivative thermogravimetric (TGA-DTG) studies. The melting and crystallization temperatures were recorded from the DSC thermograms. The peak melting temperature of PA6 reduced from 217 °C to 186 °C for 0.5 ml SbCl5 doped films. The peak of crystallization observed at 182 °C for pure films was absent, for the doped samples. The peak degradation temperatures for both pure and doped samples were above 400 °C, revealing the thermal stability of both materials. The thermally stable, semi-crystalline and semiconducting polymer films, we suggest, would be suitable for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Recently, plasma process-induced damage (PID) has garnered significant interest in the design of thin dielectric films implemented in semiconductor devices. Silicon nitride (SiN) films, a material of interest in strain engineering, are found to suffer from PID because they are exposed to various plasmas during device manufacturing processes. Only a limited amount of experimental evidence is available at present regarding plasma-induced mechanical property changes of SiN films. In this study, we investigated the mechanical property change in SiN and SiO2 films using a cyclic nanoindentation technique. We focused on the contact stiffness (S) as the principal mechanical property parameter. Firstly, a single loading/unloading test confirmed an increase in S after Ar and He plasma exposures. Subsequently, we examined the time-dependent features of damaged SiN and SiO2 films under cyclic loading/unloading. From the cyclic test, an increase in S was seen with the number of loading/unloading cycles (N) for both SiN and SiO2 films. A larger increase in S was observed for the damaged SiN, while no significant increase was seen for the damaged SiO2 films. The observed increase in S and its time dependence are attributed to the strain developed by the created defects (e.g. interstitial species) and the reconstruction and stabilization of plasma-damaged Si–N networks with created defects, respectively. The time-dependent S analysis under cyclic loading/unloading is useful for evaluating the effects of PID on the mechanical properties of thin films. [ABSTRACT FROM AUTHOR]

Engineering the dielectric constant (ε) to lower the exciton binding energy of the light‐absorbing semiconductor can improve organic photovoltaic (OPV) device performance. Here, a series of materials are reported with 2‐(3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene)malononitrile (INCN) acceptor end groups and a central glycolated bis(4H‐cyclopenta[2,1‐b:3,4‐b′]dithiophene) unit with large low‐frequency (εlf = 7.4–7.9 at 0.1–0.2 MHz) and optical‐frequency (εopt up to 6.6 at 2 × 1014 Hz) dielectric constants. The INCN end groups differed in whether they were protonated, chlorinated, or fluorinated, with the latter having the highest εopt. An εopt of 6.6 is predicted to lead to a low exciton binding energy of ≈0.04 eV. Time‐resolved microwave conductivity measurements showed a temperature‐dependent yield–mobility product, with it increasing linearly from 340 K. The onset temperature was near that required to overcome the calculated exciton binding energy and indicates increased free charge generation in a homojunction film. Room temperature transient absorption spectroscopy revealed that photoexcitation rapidly converted to a lower energy state that was consistent with the formation of polarons or a charge transfer state. This work provides experimental evidence of the importance of εopt for the generation of free charges, and a strategy for development of efficient single chromophore homojunction OPV devices. [ABSTRACT FROM AUTHOR]

Exciton–polariton condensates featuring collective coherence and large nonlinearities are promising for advancing coherent light sources and functional devices. Nevertheless, their reliance on planar cavities with large lateral device footprints and mode volumes hinders device integration. Plasmon–exciton–polaritons (PEPs), arising from the strong coupling between excitons and plasmons, provide an intriguing platform to explore emergent polariton condensation at the nanoscale due to their ultrasmall mode volumes in metal nanoparticles. However, the substantial radiative and Ohmic losses in metals hamper PEPs condensation, particularly in the short wavelength range (<600 nm). Here, a method is proposed to address metal losses by integrating organic semiconductor neat films onto plasmonic lattices. The use of organic semiconductors with large transition dipole moment and low non‐radiation loss enables efficient coupling between massive excitons and lattice plasmons, leading to high‐density PEPs. This ensures a macroscopic number of polaritons populating the low‐lying band edge at relatively low fluences to obtain bosonic stimulation, resulting in PEP condensation. By tailoring the band structures of plasmonic lattices, the condensation of PEPs are further manipulated into different energy states. These findings offer valuable insights for the design of PEP systems and all‐optical polaritonic devices. [ABSTRACT FROM AUTHOR]

Bio-artificial photosynthetic systems can reduce CO2 into multicarbon compounds by simulating natural photosynthesis. Here, inspired by organic photovoltaic structures, we demonstrate a bio-artificial photosynthetic system based on the hybridization of polymer semiconductor films and bacteria. The study suggests that the polymer-based semiconductor film can efficiently drive the non-photosynthetic bacteria to convert CO2 to acetate. By systematically characterizing the charge transport behavior of the bio-artificial photosynthetic system, the bulk-heterojunction structure and charge transport layers are proven to enhance the system performance markedly. The scalable floating artificial bio-leaf system can produce acetate to gram scale in a week. Notably, the semiconductor film is easy to recycle and maintains stable performance, showing good sustainable production capability of the system. A quasi-solid-state artificial bio-leaf is successfully prepared using agar to simulate the morphology and function of natural leaves. Last, the acetate production converted from CO2 was used to grow yeast for food production, thus achieving a complete simulation of natural photosynthesis. [ABSTRACT FROM AUTHOR]

Photodetectors are a key sensing component in enabling emerging technologies. For weak light detection, phototransistors with high responsivity are needed. Furthermore, the ability to fabricate phototransistors using solution processing techniques will enable new form factors, including flexible and large‐area devices. In this work, a novel approach for synthesizing a photosensitive organic/inorganic hybrid semiconducting thin film through solution processing is introduced. The approach involves hierarchical patterning of semiconducting carbon nanotubes (CNTs) with poly(3‐hexylthiophene‐2,5‐dyl) (P3HT) through solution‐phase heterogeneous crystallization. The fabricated hybrid phototransistors are qualified through electrical testing at varied illumination profiles within the visible light range. At a wavelength of 470 nm with an optical excitation power of 0.37 µW cm−2, the device exhibits photoresponsivity of 3.53 × 105 AW−1, surpassing other solution‐processed, non‐lead‐containing devices in the literature. The optical response extends from both photogating (low excitation power) and photon‐induced carrier generation (high excitation power). The detectivity of the device is ≈8.7 × 1010 Jones. The transient response includes a rise time of 100 ms and a fall time of 200 ms which is similar to the metrics of other low‐dimensional photodetectors. These findings highlight the prospects of the solution‐processed P3HT/semi‐CNT hybrid platform for advanced photodetection applications with flexible and large‐area form factors. [ABSTRACT FROM AUTHOR]

Despite recent dramatic improvements in the electronic characteristics of stretchable organic field-effect transistors (FETs), their low operational stability remains a bottleneck for their use in practical applications. Here, the operational stability, especially the bias-stress stability, of semiconducting polymer-based FETs under various tensile strains is investigated. Analyses on the structure of stretched semiconducting polymer films and spectroscopic quantification of trapped charges within them reveal the major cause of the strain-dependent bias-stress instability of the FETs. Devices with larger strains exhibit lower stability than those with smaller strains because of the increased water content, which is accompanied by the formation of cracks and nanoscale cavities in the semiconducting polymer film as results of the applied strain. The strain-dependence of bias-stress stability of stretchable OFETs can be eliminated by passivating the devices to avoid penetration of water molecules. This work provides new insights for the development of bias-stable stretchable OFETs. [ABSTRACT FROM AUTHOR]

Harnessing confined light on a subwavelength scale within Fano metasurfaces enhances light‐matter interaction on a flexible, low‐loss substrate. This approach enables the integration of ultra‐thin semiconducting films for designing low‐power, ultrafast switchable terahertz, and optical meta devices. Here, an ultra‐thin, ∼λ/6000 germanium overlayers of 25nm or 50nm is thermally evaporated onto a flexible Fano metallic metasurface to achieve ultrafast optical modulation of terahertz radiation. A remarkable 85% modulation depth with an ultrafast speed of 400 GHz is obtained in the resonant transmission. These ultrathin, flexible, and ultrafast functional metasurfaces pave the way for developing flexible terahertz active meta devices based on nanometric scale germanium films, offering the additional advantage of compatibility with complementary metal‐oxide‐semiconductor (CMOS) technology in microelectronics. [ABSTRACT FROM AUTHOR]

Zinc Oxide (ZnO) nanorods have great potential in several applications including gas sensors, light-emitting diodes, and solar cells because of their unique properties. Here, three low cost and ecofriendly techniques were used to produce ZnO nanorods on FTO substrates: hydrothermal, chemical bath deposition (CBD), and electrochemical deposition (ECD). This study explores the impact of such methods on the optical, structural, electrical, morphological, and photoelectrochemical properties of nanorods using various measurements. XRD analysis confirmed the hexagonal wurtzite structure of ZnO nanorods in all three methods, with hydrothermal showing a preferred orientation (002) and CBD and ECD samples showing multiple growth directions, with average particle sizes of 31 nm, 34 nm, and 33 nm, respectively. Raman spectra revealed hexagonal Wurtzite structure of ZnO, with hydrothermal method exhibiting higher E2 (high) peak at 438 cm−1 than CBD and ECD methods. SEM results revealed hexagonal ZnO nanorods became more regular and thicker for the hydrothermal method, while CBD and ECD led to less uniform with voids. UV-vis spectra showed absorption lines between 390 nm and 360 nm. Optical bandgap energies were calculated as 3.32 eV, 3.22 eV, and 3.23 eV for hydrothermal, CBD, and ECD samples, respectively. PL spectra revealed UV emission band with a small intensity peak around 389 nm and visible emission peaks at 580 nm. Temperature dependent PL measurements for ZnO nanorods indicated that the intensities ratio between bound exciton and free exciton decreases with temperature increases for the three methods. Photocurrent measurements revealed ZnO nanorod films as n-type semiconductors, with photocurrent values of 2.25 µA, 0.28 µA, and 0.3 µA for hydrothermal, CBD, and ECD samples, and photosensitivity values of 8.01, 2.79, and 3.56 respectively. Our results suggest that the hydrothermal method is the most effective approach for fabricating high-quality ZnO nanorods for optoelectronic applications. [ABSTRACT FROM AUTHOR]

This work proposes an original method that reveals the transformation dynamics of nanosized Bi films into semiconductor films of bismuth oxide (Bi2O3) and the factors affecting the low‐energy cold plasma on the electro‐optical properties of Bi2O3. In the plasma microreactor with a photosensitive GaAs:Cr electrode, the transformed Bi films 400–1100 nm thick are analyzed by X‐ray diffraction to determine the crystal structure of Bi2O3 and by an electron probe microanalyzer to explore the evolution of the composition. The morphological properties of the Bi films exposed to electron–ion flow are examined by processing the scanning electron microscope images. It is found that as a result of the combined effect of photoactive illumination, charged particles, and active plasma components: 1) an absorption spectrum of a new substance is formed in the range λ = 330–1100 nm; 2) the optical width of the bandgap of the resulting substance is Eg ≈ 3 eV, which satisfactorily coincides with the width of the bandgap of Bi2O3; and 3) to overcome the potential barrier and formation of semiconducting Bi2O3 film energy is required, which is provided by the combined kinetic energy of electrons and negatively charged oxygen ions bombarding on the Bi film. [ABSTRACT FROM AUTHOR]

Thin films of BiOCl, BiOBr, and BiOI (BiOX) were deposited by thermal evaporation for their potential application in the decontamination of water and air through their photocatalytic activity, which was compared among the three. The BiOX thin films were subjected to characterization through X-ray diffraction, high-resolution transmission electron microscopy, and scanning electron microscopy. Additionally, the optical properties were determined from the diffuse reflectance spectrum obtained with a spectrophotometer. To assess the efficacy of the semiconductor films in water decontamination, the evolution of rhodamine B discoloration and its mineralization was monitored by measuring total organic carbon. The decontaminating activity in the air was evaluated in a gas reactor, measuring the conversion of NOx-type gases. The results demonstrated that the thin films of the three oxides exhibited decontaminating photocatalytic activity in both water and air. However, notable distinctions were observed in the photocatalytic activities of the three bismuth oxyhalides in water, while in air, they exhibited similarities. In aqueous environments, the mineralization percentages exhibited notable variation after 96 h, with the BiOBr film displaying a value of 9.2%/mg and the BiOCl film a value of 3.9%/mg. In contrast, the NO conversion rate in the air was approximately 0.6%/mg for the three oxyhalide films. [ABSTRACT FROM AUTHOR]

Semiconducting photoresists hold great promise for scale‐up manufacturing of organic field‐effect transistors (OFETs) for integrated organic electronics. While photolithographic p‐type OFETs have achieved a considerable balance among patterning precision, electrical properties and process stability, it remains challenging for n‐type OFETs due to the inherent limited mobility and ambient instability. Herein, a n‐type semiconducting photoresist (SPr) is developed that is compatible with photolithography procedures. By utilizing the solvent‐driven force, a self‐encapsulated blend film with gradient semiconductor phase is prepared, where the underneath transistor active layer is protected by the upper cross‐linked network, avoiding solvent erosion and air doping. As such, a mobility up to 1.1 cm2 V−1 s−1 that is comparable with amorphous Si is achieved, with remained mobility by ≈90% after long‐term exposure to developer and stripper or atmospheric conditions. The sub‐micrometer patterning accuracy of SPr enables the fabrication of organic transistor arrays with a density of 9 × 105 units cm−1, which is comparable to other state‐of‐the‐art devices fabricated by the printing or photolithography, demonstrating immense potential in integrated organic electronics. [ABSTRACT FROM AUTHOR]

Unipolar p‐ and n‐type organic field‐effect transistors (OFETs) are essential for constructing organic circuits and complementary designs crucial for high‐performance electronics. Traditionally, fabricating these transistors requires separate p‐type and n‐type organic semiconductors (OSCs), which complicates the process due to intricate patterning, protection of the first OSC layer, and considerable material wastage. In this work, an innovative approach is introduced, inspired by silicon transistor fabrication to obtain unipolar OFETs, employing a single ambipolar OSC in conjunction with doped organic semiconductor films (DOSCFs) as electrodes. This results demonstrate that OFETs with DOSCF electrodes suppress ambipolarity dramatically and achieve on/off ratios that are two to three orders of magnitude higher than those with metal electrodes, along with excellent stability. The unipolar characteristics of the devices are attributed to the unique work function properties and the intrinsic charge carrier behavior of the DOSCF electrodes. Significantly, inverter circuits utilizing these unipolar transistors outperformed traditional ambipolar transistors with metal electrodes, achieving a fivefold increase in voltage gain. This novel strategy promises to enhance the practicality and economic viability of organic electronics, paving the way for more sustainable and high‐performance circuit designs. [ABSTRACT FROM AUTHOR]

Growing crack-free, epitaxial ultrawide-bandgap semiconductor films on cost-effective, large-area substrates, such as AlN on Si, poses a significant challenge due to substantial lattice and thermal expansion mismatches. We introduce an approach to mitigate tensile strain or reverse strain signs between the substrate and the AlN layer, thereby suppressing crack formation during the heteroepitaxial growth of thick III-N films. This approach introduces ductile metallic interlayers, specifically Au, to change the strain state of AlN from in-plane tensile to compressive, without initiating cracks. Furthermore, the Au interlayer is grown epitaxially as a single crystal, which prevents the transfer of tensile strain into the AlN film, as confirmed by x-ray diffraction and transmission electron microscopy. We demonstrate crack-free AlN films exceeding 1 μm in thickness. These findings hold significant promise for advancing the field of ultrawide-bandgap semiconductor materials, with potential applications in electronic, optoelectronic, sensing, and energy device applications. [ABSTRACT FROM AUTHOR]

[Display omitted] The effect of UV irradiation on sol–gel prepared ZnO films subjected to mild thermal annealing was investigated, with special attention to their structural and surface properties. Sol–gel processes, including a high-temperature annealing stage, have been adapted to the requirements of flexible electronics for in situ synthesis of semiconductor ZnO films on polymer substrates at lower temperatures due to UV irradiation. Application of UV radiation with emission peaks at 185 and 254 nm to films annealed at 180 °C made it possible to obtain ZnO films with Zn/O ratios of ca. 1, which cannot be achieved by heat treatment alone. [ABSTRACT FROM AUTHOR]

Band structure of a semiconducting film critically determines the charge separation and transport efficiency. In antimony selenosulfide (Sb2(S,Se)3) solar cells, the hydrothermal method has achieved control of band gap width of Sb2(S,Se)3 thin film through tuning the atomic ratio of S/Se, resulting in an efficiency breakthrough towards 10 %. However, the obtained band structure exhibits an unfavorable gradient distribution in terms of carrier transport, which seriously impedes the device efficiency improvement. To solve this problem, here we develop a strategy by intentionally regulating hydrothermal temperature to control the chemical reaction kinetics between S and Se sources with Sb source. This approach enables the control over vertical distribution of S/Se atomic ratio in Sb2(S,Se)3 films, forming a favorable band structure which is conducive to carrier transport. Meanwhile, the adjusted element distribution not only ensures the uniformity of grain structure, but also increases the Se content of the films and suppress sulfur vacancy defects. Ultimately, the device delivers a high efficiency of 10.55 %, which is among the highest reported efficiency of Sb2(S,Se)3 solar cells. This study provides an effective strategy towards manipulating the element distribution in mixed‐anion compound films prepared by solution‐based method to optimize their optical and electrical properties. [ABSTRACT FROM AUTHOR]

Highly stretchable aerogel films are attractive for advanced next‐generation stretchable electronics. However, it is a great challenge to achieve high stretchability for aerogel films. Here, several types of unprecedented ultra‐stretchable semiconducting polymer‐based aerogel films with crimpled porous structures are developed via crosslinking and template methods combined with uniaxial and biaxial pre‐stretching strategies. The semiconducting aerogel films obtained by uniaxial pre‐stretching exhibit ultrahigh stretchability up to 100–200%, while those obtained by biaxial pre‐stretching show high biaxial stretchability up to 50%. The resulting aerogel films show strain‐insensitive electrical and joule heating properties. A prototype of the aerogel film‐based stretchable organic electrochemical transistor (OECT) is developed for the first time. Benefiting from their unique porous structures, the aerogel film‐based OECTs exhibit enhanced on/off ratio and transconductance compared with corresponding dense film‐based OECTs, high stretchability up to 100%, and high stretching stability with 10 000 stretching cycles under 30% strain. It is demonstrated that the aerogel film‐based OECTs can be applied as high‐performance stretchable artificial synapses and biosensors. This work gives a versatile strategy toward highly stretchable aerogel films promising for flexible electronics. [ABSTRACT FROM AUTHOR]

The market demand for optoelectronic devices is increasing, leading to a need for low‐cost, high‐performance image sensors that can operate effectively in challenging environments such as darkness and fog. The emerging 2D transition metal dichalcogenides (TMDs) have garnered significant interest due to their exceptional optoelectronic properties and compatibility with silicon (Si) complementary metal oxide semiconductor (CMOS) technology. However, the large‐scale synthesis of TMD films and uniform preparation of photodiode arrays remain challenging. This paper reports a synthesis method for heteroepitaxial growth of 2H‐ molybdeum diyelluride (MoTe2) semiconducting films on 3D wafer‐level Si substrates. Using this method, arrays of 2H‐MoTe2/Si heterojunction photodiodes are prepared that demonstrate excellent uniformity and 100% device yield. The photodiodes exhibit satisfactory optoelectronic properties, including a small dark current maintained within a range of 1–3 nA and a maximum responsivity of 521.1 mAW−1 under near‐infrared light at 800 nm, with rise and fall times of less than 4 ms. To demonstrate the image‐sensing capabilities of the photodiode array under visible and near‐infrared (NIR) light illumination, a complete imaging system is designed.The MoTe2/Si photodiode arrays examined in this study offer a practical solution for integrating Si‐based readout circuits and photodetector arrays on a single chip. [ABSTRACT FROM AUTHOR]

High-performance alloy thin films and large-sized thin film wafers for infrared applications are the focus of international researchers. In this study, doped Ge1−xSnx and Ge1−yBiy semiconductor alloy films were grown on a 5-in. silicon (Si) wafer using high-quality Ge films as buffer layers. An efficient technique is presented to reduce the dark current density of near-infrared photoelectric devices. By using boron for p-type doping in Ge1−xSnx films and bismuth (Bi) for n-type doping in Ge1−yBiy films, an all-thin film planar nano-p-i-n optoelectronic device with the structure n-Ge1−yBiy/i-GeSn/p-Ge1−xSnx/Ge buffer/Si substrate has been successfully fabricated. The photoelectric performance of the device was tested, and it was found that the insertion of p-Ge1−xSnx/Ge films reduced the dark current density by 1–2 orders of magnitude. The maximum photoresponsivity reached up to 0.8 A/W, and the infrared photocurrent density ranged from 904 to 935 μA/cm2 under a +1 V bias voltage. Furthermore, the device is capable of modulating a terahertz wave using a voltage signal with a modulation bandwidth of 1.2 THz and a modulation depth of ∼83%, while the modulation rate is 0.5 MHz. This not only provides a clear demonstration of how doped alloy films and the development of nano-p-i-n heterojunctions will improve photoelectric devices' performance in the near-infrared and terahertz bands, but it also raises the possibility of optoelectronic interconnection applications being achieved through a single device. [ABSTRACT FROM AUTHOR]

This work presents the synthesis of para-quinone methides (p-QMs), which were deposited as films using the high vacuum sublimation technique after being chemically characterized. The p-QMs films were characterized morphologically and structurally using scanning electron microscopy, atomic force microscopy, and X-ray diffraction. In addition, their optical behavior was studied by means of ultraviolet–visible spectroscopy, and the optical gaps obtained were in the range of 2.21–2.71 eV for indirect transitions, indicating the semiconductor behavior of the p-QMs. The above was verified through the manufacture and evaluation of the electrical behavior of rigid semiconductor devices, in which fluorine-doped tin oxide-coated glass slides (FTO) were used as an anode and substrate. Finally, as an original, ecological, and low-cost application, the FTO was replaced by substrates and anodes made from recycled Tetra Pak®, generating flexible semiconductor devices. Although the electrical current transported depends on the type of p-QMs, the substituent in its structure, and the morphology, the kinds of substrate and anode also influence the type of electrical behavior of the device. This current–voltage study demonstrates that p-QM2 with 4-Cl-Ph as a radical, p-QM3 with 4-Et2N-Ph as a radical, and p-QM6 with 5-(1,3-benzodioxol) as a radical can be used in optoelectronics as semiconductor films. [ABSTRACT FROM AUTHOR]

Our study of magnetization switching in crystalline (Ga,Mn)(As,P) ferromagnetic semiconductor (FMS) film by spin-orbit torque (SOT) has revealed an unexpected increase in critical switching current as the in-plane magnetic bias field is increased beyond a certain point. This intriguing behavior is ascribed to depolarization of spin-polarized current induced by the application of bias field perpendicular to the direction of current carrier spins. This is particularly interesting, because the bias field is itself a necessary requirement for achieving the deterministic SOT magnetization switching. To gain understanding of this unexpected behavior, we incorporated the process of spin depolarization into micromagnetic simulation study of SOT magnetization switching in the (Ga,Mn)(As,P) system. Through simulations that include effects of spin depolarization, we were able to replicate the observed increase in the required critical switching current as the in-plane bias field is increased. Furthermore, our study demonstrates that the dependence of critical switching current on bias field can be quantitatively described by adjusting magnetic anisotropy parameters of the film. This study not only enhances our understanding of SOT phenomena but also offers valuable insights for tailoring and optimizing FMS materials for spintronic applications. [ABSTRACT FROM AUTHOR]

In this work, we developed an optimized ultrasonic spray pyrolysis device for obtaining metal oxide films. The key benefit of this facility lies in its cost-effectiveness and its ability to consistently coat extensive surfaces without sacrificing the integrity of the semiconductive films, thus streamlining the manufacturing process of semiconductor films. The resulting films exhibit the following attributes: the thickness of the deposited layer is approximately 400 nm, while the diameters of ZnO1-xSx nanocrystals range from 50 to 200 nm, oriented perpendicular to the crystallographic orientation (111). In the production of nanorods, the average height is estimated to be approximately 30-50 nm, with a density of 2.9×1011 cm-2 being indicated. [ABSTRACT FROM AUTHOR]

This work aims to examine the optoelectrical, optical, and structural properties of novel polycrystalline SrZnO2 layers fabricated by a cost-effective nebulizer spray pyrolysis procedure at varying thicknesses (237, 395, 468, and 529 nm). The X-ray diffractograms have been used in this work to study the structure of the SrZnO2 films. The SrZnO2 films possessed an orthorhombic structure. The computational analysis involved determining the structural indices, including grain size, dislocation density, and lattice strain, of the SrZnO2 films. Energy dispersive X-ray analysis has been used to verify the stoichiometry of these SrZnO2 films. The surface morphology of the SrZnO2 layers has been studied using the field-emission scanning electron microscope. The optical characteristics of the SrZnO2 films have been investigated by the spectrophotometric measurements in the range 400–2500 nm. The optical results of the SrZnO2 films depicted that the enhancement of the refractive index, Urbach's energy, and absorption coefficient of these films by boosting the thickness. Meanwhile, the improvement in the crystallization process led to a small decrease in the optical band gap energy values of the SrZnO2 layers from 2.91 to 2.68 eV as the film thickness grew. Furthermore, the analysis of the optoelectrical characteristics of the SrZnO2 films showed that the boost in film thickness enhanced the values of plasma frequency, optical resistivity, optical carrier concentration, optical mobility, and optical conductivity. The nonlinear optical properties of the SrZnO2 layers have been boosted by the thickness growth. On the other hand, the hot probe equipment revealed that both the SrZnO2 layers exhibited n-type semiconducting characteristics. The acquired results validate the wide bandgap semiconductor nature of these films. Consequently, it is advisable to use them as a window layer in various solar cell applications. The electrical results illustrated that the estimated activation energy of the SrZnO2 films decreases as the thickness rises. [ABSTRACT FROM AUTHOR]

Here, the effect of thermal annealing (TA) on the stability of solution‐sheared thin films of the semiconducting polymer poly[2,5‐bis(2‐octyldodecyl)pyrrolo[3,4‐c]pyrrole‐1,4(2H,5H)‐dione‐3,6‐diyl)‐alt‐(2,2′;5′,2′';5′',2′"‐quaterthiophen‐5,5′"‐diyl)] (PDPP4T) against the original coating solvent is studied, and it is shown that TA significantly improves the solvent resistance of semiconducting polymer films. Specifically, after the thin films are annealed at or above a critical temperature, the thin film thickness is largely retained when exposed to the original solvent, while for lower annealing temperatures material loss occurs, i.e., the thin film thickness is reduced due to rapid dissolution. The results of various techniques including grazing‐incidence wide‐angle x‐ray scattering (GIWAXS), atomic force microscopy (AFM), and ultraviolet‐visible‐near infrared (UV–vis‐NIR) absorption spectroscopy suggest physical changes as the cause for the increased solvent resistance. Such annealed films also show stable electrical characteristics in bottom‐gate, top‐contact (BGTC) organic field‐effect transistors (OFETs) even after solvent exposure. In initial tests, a multitude of technologically relevant polymers show such behavior, underlining the potential impact of such temperature treatments for the fabrication of multi‐layer polymer devices. [ABSTRACT FROM AUTHOR]

Directional ionic migration in ultra-thin metal-oxide semiconductors under applied electric fields is a key mechanism for developing various electronic nanodevices. However, understanding charge transfer dynamics is challenging due to rapid ionic migration and uncontrolled charge transfer, which can reduce the functionality of microelectronic devices. This research investigates the supercapacitive-coupled memristive characteristics of ultra-thin heterostructured metal-oxide semiconductor films at TiO2-In2O3/Au Schottky junctions. Using atomic layer deposition (ALD), we nano-engineered In2O3/Au-based metal/semiconductor heterointerfaces. TEM studies followed by XPS elemental analysis revealed the chemical and structural characteristics of the heterointerfaces. Subsequent AFM studies of the hybrid heterointerfaces demonstrated supercapacitor-like behavior in nanometer-thick TiO2-In2O3/Au junctions, resembling ultra-thin supercapacitors, pseudocapacitors, and nanobatteries. The highest specific capacitance of 2.6 × 104 F.g−1 was measured in the TiO2-In2O3/Au junctions with an amorphous In2O3 electron gate. Additionally, we examined the impact of crystallization, finding that thermal annealing led to the formation of crystalline In2O3 films with higher oxygen vacancy content at TiO2-In2O3 heterointerfaces. This crystallization process resulted in the evolution of non-zero I-V hysteresis loops into zero I-V hysteresis loops with supercapacitive-coupled memristive characteristics. This research provides a platform for understanding and designing adjustable ultra-thin Schottky junctions with versatile electronic properties. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue of the journal Coatings titled "Recent Advances in the Development of Thin Films." The issue includes thirteen contributions, including two reviews and eleven research articles, covering various aspects of thin films. The articles explore topics such as deposition and characterization techniques, synthesis and characterization of thin films with specific properties, assessment of mechanical and electrical properties, and applications of thin films in sensing and solar cell technologies. The issue highlights the ongoing innovation in the field of thin films and their potential applications in various industries. [Extracted from the article]

Theoretical description of electronically excited states of molecular aggregates at an ab initio level is computationally demanding. To reduce the computational cost, we propose a model Hamiltonian approach that approximates the electronically excited state wavefunction of the molecular aggregate. We benchmark our approach on a thiophene hexamer, as well as calculate the absorption spectra of several crystalline non-fullerene acceptors, including Y6 and ITIC, which are known for their high power conversion efficiency in organic solar cells. The method qualitatively predicts the experimentally measured spectral shape, which can be further linked to the molecular arrangement in the unit cell. [ABSTRACT FROM AUTHOR]

It is usually believed that doping with photosensitizers capable of generating singlet oxygen (1O2) plays a pivotal role in enhancing the afterglow performance of semiconducting polymer nanoparticles (SPNs). However, the effect of doping photosensitizer bearing electron‐withdrawing groups has not been reported. Here we report the effect of doping with six photosensitizers possessing different electron‐withdrawing groups on the afterglow performance of SPNs using poly[(9,9‐di(2‐ethylhexyl)‐9H‐fluo‐rene‐2,7‐vinylene)‐co‐(1‐methoxy‐4‐(2‐ethylhexyloxy)‐2,5‐phenylenevinylene)] (PF‐MEHPPV) as substrate. It was found that the afterglow performance of SPNs was significantly influenced by doping with photosensitizers bearing electron‐withdrawing groups. For the doped photosensitizers with strong electron‐withdrawing groups, the stronger the electron‐withdrawing ability of the group, the worse of the afterglow performance of the SPN regardless of the 1O2 generation ability of the photosensitizer. When the doped photosensitizer exhibited weak or none electron‐withdrawing effect, the 1O2 generation ability of the photosensitizer played a dominant role on the afterglow performance of the SPNs. This work deepens the understanding of the design and synthesis of SPNs with different afterglow properties. [ABSTRACT FROM AUTHOR]

Sustainable energy production is urgently needed due to the high environmental costs associated with the use of fossil fuels. Green hydrogen produced by photoelectrocatalysis is an emerging solution for meeting the global energy demand. Herein, we discuss the physicochemical properties and electrochemical hydrogen production of SnS films prepared via chemical bath deposition at 40 °C under visible light. The synthesis times were varied to obtain films with thicknesses of 102, 295, and 495 nm deposited at 3, 4, and 6 h, respectively. All samples were annealed at 400 °C and exhibited an orthorhombic phase. The direct optical bandgap transition decreased from 1.44 to 1.25 eV with increasing sample thickness. With increasing synthesis time, a significant amount of Sn was deposited, forming a surface monolayer of amorphous SnO 2 , which improved the electronic conductivity of the samples. However, the presence of SnO 2 reduced the number of sulfur vacancies, which is crucial for the hydrogen evolution reaction. Therefore, the SnS film synthesized for 3 h exhibited the highest hydrogen evolution rate, which reached 18,826 μmol/m2-h. These results suggest the feasibility of using SnS films for photoelectrochemical hydrogen generation. [Display omitted] • Stable SnS films were prepared using chemical bath deposition. • The synthesis time is crucial for determining optoelectronic properties. • Intrinsic native defects and Sn excess-controlled H 2 photoproduction. • The maximum H 2 production was obtained at the lowest deposition time. [ABSTRACT FROM AUTHOR]

In the face of the growing energy crisis and environmental challenges, substantial efforts are now directed toward sustainable clean energy as a replacement for traditional fossil fuels. CO2 photoreduction into value‐added chemicals and fuels is widely recognized as a promising approach to mitigate current energy and environmental concerns. Photocatalysts comprising single atoms (SAs) supported on two‐dimensional (2D) semiconducting materials (SAs‐2DSemi) have emerged as a novel frontier due to the combined merits of SA catalysts and 2D materials. In this study, we review advancements in metal SAs confined on 2DSemi substrates, categorized into four groups: (1) metal oxide‐based, (2) g‐C3N4‐based, (3) emerging, and (4) hybridized 2DSemi, for photocatalytic CO2 conversion over the past few years. With a particular focus on highlighting the distinct advantages of SAs‐2DSemi, we delve into the synthesis of state‐of‐the‐art catalysts, their catalytic performances, and mechanistic elucidation facilitated by experimental characterizations and theoretical calculations. Following this, we outline the challenges in this field and offer perspectives on harnessing the potential of SAs‐2DSemi as promising photocatalysts. This comprehensive review aims to provide valuable insights for the future development of 2D photocatalytic materials involving SAs for CO2 reduction. [ABSTRACT FROM AUTHOR]

Two-dimensional metal thin films have received extensive research attention owing to their distinctive physical and chemical properties. The direct synthesis of highly anisotropic monatomic metal layers is challenging owing to the symmetric non-oriented bonds of metals. In this study, we present a one-step synthesis method for preparing single-atom-thick gold films via high-temperature heating. During substrate synthesis, the surface-hanging bonds anchor the gold atoms individually, resulting in self-assembled loaded monolayer gold films. Density function theory calculations show that gold atoms prefer to anchor along the chain direction, resulting in monolayer films with good homogeneity and stability. The electronic structure of these films is completely different from that of bulk gold. This property may endow the films with potential for applications in magnetism, optics, and catalysis. [ABSTRACT FROM AUTHOR]

This study explores the new findings of in-plane mechanical forces on electric currents and thermal control in piezoelectric semiconductors. The thermo-electro-elastic theory is considered based on the thermo-piezoelectricity theory and drift–diffusion theory for semiconductors. A two-dimensional nonlinear model for in-plane deformations of piezoelectric semiconductor films is developed, where thermo-elastic, pyroelectric and thermoelectric couplings are involved. The newly developed nonlinear equations are directly solved based on the finite element method, while linearized equations derived from the nonlinear theory and corresponding analytical solutions are also obtained as a reference for validation. Our findings indicate that the in-plane mechanical forces exerted on piezoelectric semiconductors significantly influence both currents and thermal fluxes through piezoelectric coupling. Specifically, the angle of in-plane mechanical force relative to the c-axis significantly impacts the currents, with the potential to suppress, enhance or alter the direction, thereby affecting the temperature field. Based on these findings, an application simulation that focuses on mechanically induced current manipulation and thermal control is introduced and realized. [ABSTRACT FROM AUTHOR]

The primary purpose of this article is to synthesize electrochemically a binary semiconductor material ZnS that is generally used for manufacturing solar cells. It has been shown that the properties and composition of the deposits are closely linked to the synthesis conditions, namely the applied potential, the electrolyte concentration and its composition. The electrodeposition was realized from an acidic medium with a pH ranging from 3.5 to 4.5 and containing respectively 0.02 M of zinc chloride (ZnCl2), 0.02 M of sodium thiosulphate (Na2S2O3), and 0.15 M of trisodium citrate (Na3C6H5O7) as complexing agent. The deposition mechanism of ZnS binary alloys was investigated using various electrochemical techniques. ZnS thin films were electrochemically deposited on a tin-doped indium oxide (ITO) substrate in one single step, at a potential of −1 V/SCE. The effects of the concentration ratio ([zinc]/[sulfur]) on the electrochemical, optical, and compositional properties of thin films as well as their surface morphology were also investigated. [ABSTRACT FROM AUTHOR]

Solution-based processing of two-dimensional (2D) materials has garnered significant interest as a facile and versatile route for the large-scalable production of 2D material films. Despite the benefits in process, these films were not considered suitable for device applications during the early stages of research because their electronic properties were far from those of 2D materials obtained through micromechanical exfoliation or chemical vapor deposition. Due to the small lateral dimensions and polydisperse thickness of constituent 2D nanosheets, the resulting film tends to be porous and exhibits numerous inter-sheet junctions, primarily contacting edge-to-edge. This nanosheet morphology leads to poor electrical conductivity of the network, and also hinders the film functioning as a semiconductor or an insulator. To produce ultrathin 2D nanosheets with narrow thickness distribution and large lateral sizes, various chemical exfoliation strategies have been explored, but these are limited by long process times, involvement of harsh chemicals, and/or undesired structural damage or phase changes. Recent breakthroughs in electrochemical exfoliation using tetraalkylammonium intercalants enabled the production of high-quality 2D nanosheets with structural characteristics favorable for producing ultrathin, conformal films of 2D materials, which allow for scalable production of high-performance electronic components that can readily be assembled into functional devices via solution-processing. In this review article, we aim to offer an extensive introduction solution-based processing techniques for acquiring 2D nanosheets, their subsequent assembly into thin films, and their diverse applications, primarily focusing on electronics and optoelectronics but also extending to other fields. Remaining challenges and potential avenues for advancement will also be discussed. [ABSTRACT FROM AUTHOR]

RF reactive sputtering was used to deposit copper tantalum nitride (CuTaN2) films from a Cu/Ta target in an environment containing a mixture of argon and nitrogen at two different substrate temperatures: room temperature and 200 °C. The films were studied by SEM, EDS, XRD, Raman spectroscopy, spectrophotometry, and resistivity measurements. The deposition conditions significantly impacted the morphology of the films, which varied from smooth, void-free films at high nitrogen concentrations and at room temperature substrates to cauliflower-like grains with voids at low nitrogen contents and elevated substrate temperatures. Despite the target's 1:1 Cu: Ta ratio, the stoichiometric analysis showed a lower Ta content in the deposited film. The films produced on silicon substrates were polycrystalline, whereas those deposited on glass substrates were amorphous. The band gap (0.9 eV to 1.55 eV) and film resistivity (20 kΩ-cm to 76 kΩ-cm) are strongly affected by the nitrogen fraction in the sputtering gas. Increasing the nitrogen percentage in semiconductor films results in smoother films with larger bandgaps (approximately 1.5 eV), higher resistivity, and compositions closest to those of stoichiometric CuTaN2. [ABSTRACT FROM AUTHOR]

In this study, Cadmium Sulfide (CdS) semiconductor films are electrodeposited on Indium Tin Oxide (ITO) substrates at 80 °C base temperature for different boric acid (H3BO3) ratios. The effect of boric acid on these films is investigated. For this, first of all, the structural change of the films is examined. Among the films obtained with different boric acid ratios, the optimum film is achieved with 0.06 m boric acid doped. From the basic absorption spectra (αhʋ) of the obtained CdS:B films, the variation of hʋ is drawn and it is determined that the CdS:B semiconductor films has a direct band transition. From the basic absorption spectra of the obtained CdS:B films, it is observed that the CdS:B semiconductor films has a direct band transition. In addition, the optical energy bandgap values obtained are in agreement with the values in the available literatures. The results of the structural, optical, and morphological properties of the films produced in this study indicate that among the selected additive ratios, 1% boric acid gives the best and optimum deposition condition. The thin films obtained are also found to be useful as absorber layers in photovoltaic solar cells. [ABSTRACT FROM AUTHOR]

In the recent years, the using of fossil energy source-based fuels are delivering to the predetermined nature, health and environmental exposure, there is a universal necessitate prepared to well improvement and consumption of renewable energy source and apparatus. With the rapid growth of human life, energy is more essential. The explosive growth of population and energy consumption demands are the exclusive issue of the present world. In response to the energy demands, the growth of highly efficient energy conversion and storage devices. With increasing energy demands and environmental pollution, there is a requirement of the world to great some novel conducting materials consist of Perovskite solar cells (PSCs) which is delivered that excellent photoconversion efficiencies (PCE) compare with the other silicon supported photovoltaics, and also semiconducting materials for the conversion of substitute energy sources and preparation of high high-performance semiconductor devices. Semiconducting thin films play an indispensable role in fashionable science and electronic technology. Among them, the II–VI compound semiconductor thin films are an important class of materials, and they are generally comprehensive wide-band gap materials. In addition, the un-doped and rare-earth metal ions doped zinc selenide (ZnSe) thin films are currently the most demanding and technologically important materials, which have the potential for optoelectronic devices (solar cells, photoelectrochemical cell and light emitting diodes) and are active throughout the entire visible spectrum extending into the infrared wavelengths. Various techniques for depositing thin coatings on these substances are utilized to a greater extent. In this review, the most recent advanced techniques in the application of semiconducting materials-based thin films were produced in various energy-generated fields, particularly solar cells, with a major focus on a review of recent progress in the development of various types of ZnSe thin film-based material for high-performance semiconducting thin film material for solar cell application. Lastly, the advantages and material challenges of semiconductor-based thin films for future sanitary energy device process are described. [ABSTRACT FROM AUTHOR]

Semiconducting materials are pivotal in various fields, such as solar cells, LEDs, photovoltaic cells, etc. A nature‐friendly chitosan is a good film‐forming, water‐soluble polymer that is modified to a small band‐gap polymer for various optoelectronic applications. Choline chloride:ethylene glycol:glycerin (1:1:1) deep eutectic solvent (DES)‐modified activated carbon is incorporated into the chitosan matric and this composite is fabricated into thin films via spin coating methodology. The obtained films are subjected to multiple studies such as scanning electron microscopy (SEM), X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), impedance spectroscopy, and UV–vis spectroscopy to perceive the thin‐films microstructure, morphology, conductance, band gap, and optical nature. The integration of DES‐modified activated carbon has significantly improved the charge transfer capacity of chitosan by reducing the band gap from 4.0 to 2.0 eV. These notable characteristics exhibited by the modified films can be key to sustainable semiconducting materials and have the potential to transform several optoelectronic applications. [ABSTRACT FROM AUTHOR]

The optical absorption coefficient is one of the fundamental properties of semiconductors and is critical to the development of optical devices. Herein, a revival of the constant photocurrent method is presented to measure sub‐bandgap absorption in wide bandgap semiconductor films. The method involves maintaining a constant photocurrent by continually adjusting the impinging photon flux across the energy spectrum. Under such conditions, the reciprocal of the photon flux for uniformly absorbed light is proportional to the absorption coefficient. This method is applied to α‐Ga2O3 and reveals that it can access the absorption coefficient from 1 × 105 cm−1 at the band edge (5.3 eV) to 0.8 cm−1 close to mid‐bandgap (2.7 eV). Changes in the steepness of the absorption curve in the sub‐bandgap region are in excellent agreement with defect states of α‐Ga2O3 reported by deep level transient spectroscopy, indicating that the technique shows promise as a probe of energetically distributed defect states in thin film wide bandgap semiconductors. [ABSTRACT FROM AUTHOR]

It is crucial to prepare high-mobility organic polycrystalline film through solution processing. However, the delocalized carrier transport of polycrystalline films in organic semiconductors has rarely been investigated through Hall-effect measurement. This study presents a strategy for building strong intermolecular interactions to fabricate solution-crystallized p-type perylene diimide (PDI) dianion films with a closer intermolecular π–π stacking distance of 3.25 Å. The highly delocalized carriers enable a competitive Hall mobility of 3 cm2 V−1 s−1, comparable to that of the reported high-mobility organic single crystals. The PDI dianion films exhibit a high electrical conductivity of 17 S cm−1 and typical band-like transport, as evidenced by the negative temperature linear coefficient of mobility proportional to T −3/2. This work demonstrates that, as the intermolecular π–π interactions become strong enough, they will display high mobility and conductivity, providing a new approach to developing high-mobility organic semiconductor materials. [ABSTRACT FROM AUTHOR]

The optical absorption coefficient is one of the fundamental properties of semiconductors and is critical to the development of optical devices. Herein, a revival of the constant photocurrent method is presented to measure sub‐bandgap absorption in wide bandgap semiconductor films. The method involves maintaining a constant photocurrent by continually adjusting the impinging photon flux across the energy spectrum. Under such conditions, the reciprocal of the photon flux for uniformly absorbed light is proportional to the absorption coefficient. This method is applied to α‐Ga2O3 and reveals that it can access the absorption coefficient from 1 × 105 cm−1 at the band edge (5.3 eV) to 0.8 cm−1 close to mid‐bandgap (2.7 eV). Changes in the steepness of the absorption curve in the sub‐bandgap region are in excellent agreement with defect states of α‐Ga2O3 reported by deep level transient spectroscopy, indicating that the technique shows promise as a probe of energetically distributed defect states in thin film wide bandgap semiconductors. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis, analysis, and utility of films comprising deep eutectic solvent (DES) grafted activated charcoal (AC) within a polyvinyl alcohol (PVA) matrix for optoelectronic device applications. The fabrication process involves the dispersion of DES functionalization AC into the PVA solution, followed by casting onto substrates with controlled drying. Comprehensive characterization encompassing X‐ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis spectroscopy, Fourier‐transform infrared spectroscopy (FTIR), and impedance spectroscopy which discerns the films microstructure, morphology, conductance, band‐gap, and optical traits. The DES grafted AC infusion with variable concentration has significantly influenced optical absorbance and reduced the band gap indicating efficient charge mobility. Furthermore, the impedance analysis has revealed the electrical conduction of the film to be 1.8 × 10−6 Ω−1 m−1. In summary, the dispersion of DES modified AC in the PVA matrix have converted the insulating PVA to a semiconducting polymeric film with reduced band‐gap and increased absorption, which present a propitious avenue for wide array of optoelectronic devices, such as thin film transistors, photovoltaics, LEDs, photodetectors, and many such applications. [ABSTRACT FROM AUTHOR]

Semiconductor films are crucial in photocatalysis applications, yet their controlled production remains challenging. Previous studies have mainly focused on deposition processes, heating rates, and doping of semiconductor oxides. In this paper, we introduce a novel method for fabricating tenorite (CuO) semiconductor films with varying precursor concentrations (0.01, 0.02, 0.04, 0.06, and 0.1 g/ml) using a dip-coating technique. We explore the impact of contact angles, 3D surface topography, and film thickness on photoactivation properties, areas with limited previous research focus. The results demonstrate that higher-concentration tenorite films (0.1 g/ml) exhibit rougher surfaces (77.3 nm), increased hydrophobicity (65.61°), improved light-harvesting ability, enhanced charge separation, and higher active oxygen output. The crystal sizes were within the range of 7.3–44.1 nm. Wettability tests show a 21.47% improvement in the 0.1 g/ml film surface under indirect sunlight compared to darkness. Transmittance rates in the 600 nm range were from 0.02 to 90.94%. The direct optical band gaps were 1.21–2.74 eV, while the indirect band gaps remained unaffected (0.9–1.11 eV). Surface morphology analysis reveals an increased presence of grains with higher concentrations. Regarding photocatalysis's impact on film morphology and copper content, SEM images reveal minimal changes in film structure, while copper content remains stable with slight variations. This suggests strong adhesion of tenorite to the film after photocatalysis. Tenorite thin films display exceptional photocatalytic efficiency, making them suitable for practical applications. [ABSTRACT FROM AUTHOR]

Organic materials and, in particular, polymer films enhanced with certain nanocrystals have a potential for wide application in electronics and optoelectronics due to their organic flexibility, lightweight, simple integration, affordable manufacturing cost, and low environmental impact of their production. The purpose of this research is to investigate the electrical properties of polymer-based composite films containing Cd1-xCuxS nanocrystals in order to determine their prospects for use as conductive layers in organic electronics and optoelectronics. The paper contains a detailed description of the synthesis method of hybrid nanocomposite films based on peroxide reactive copolymer (PRC) with Cd1-xCuxS nanocrystals. The defect structure of the films is studied by analyzing the photoluminescence spectra. Current-voltage characteristics of the films with different Cd and Cu contents in the Cd1-xCuxS nanocrystals embedded into the polymer matrix, deposited on glass substrates are measured in the dark and under light illumination. The film conductivity is found to increase with the Cu content in the Cd1-xCuxS nanocrystals. The carrier transport corresponds to the Ohm law at low voltages and the space charge limited current (SCLC) or Poole-Frenkel mechanisms at higher ones. The conductivity of the polymer-based hybrid nanocomposite films has a weak dependence on the intensity of light illumination. The explanation of the obtained experimental results is proposed. [ABSTRACT FROM AUTHOR]